Gensytskyi M.V. Fauna and morphometric variability of terrestrial molluscs (Mollusca) of the northwestern Azov Sea region.
The dissertation on competition of a scientific degree of the candidate of biological sciences (doctor of philosophy) on a specialty 091 "Biology". Melitopol State Pedagogical University named after Bohdan Khmelnytsky, Melitopol, 2021.
The aim of the work is to establish the species composition of terrestrial mollusks, their morphometric variability and patterns in the conditions of the north-western Azov Sea. To verify the goals set during the offensive tasks: To establish the current species composition of terrestrial mollusks in the north-western Priazovye. Analyze the features of the biotope distribution of terrestrial mollusks in the northwestern Azov Sea. Start using the morphological parameters of ground lightning for applied domestic species of the genera Helix, Xeropicta, Chondrula, which can be used to characterize the population. Establish patterns of morphometric variability of individual species of terrestrial mollusks. Assess the economic importance of terrestrial mollusks in the north-western Azov Sea.
The object of research is terrestrial mollusks in anthropogenically transformed and natural ecosystems of the northwestern Azov Sea region. The subject of research is the current state of fauna and biotope distribution of terrestrial mollusks and patterns of morphometric variability of dominant species in the north-western Azov Sea.
To assess the current state of the mollusk fauna, material was collected in 2017-2020 in the northwestern Azov Sea region. In total, about 7.6 thousand individuals, 20 species of terrestrial mollusks from 179 points were collected.
For the first time, a long-term field study of terrestrial mollusks in natural and anthropogenically transformed biotopes in the north-western Azov region has been carried out. The modern fauna of terrestrial mollusks includes 27 species from 12 families, of which 6 species are listed for the first time: Cochlicopa lubrica, Pupilla muscorum, Truncatellina cylindrica, Phenacolimax annularis, Euconulus fulvus, Monacha cartusiana. Regularities of biotopic distribution of terrestrial mollusks depending on the type of soils, the state of their moisture and the nature of vegetation are established. A unified method of water test has been proposed and tested to objectively assess the volume of the sink.
The most common species in terms of frequency were Chondrula tridens, Vallonia pulchella, Vallonia costata, Monacha fruticola, Xeropicta derbentina, Vitrina pellucida.
A comparative analysis of the conchological features of the terrestrial mollusk Helix albescens, collected in natural and anthropogenic habitats. Comparison of the size of Helix albescens shells from areas with different anthropogenic load showed that in the city the size of the shell is larger than in rural areas.
Xeropicta derbentina demonstrates significant variability of morphometric traits in different habitats. The color variability of shells was also assessed, according to a simplified coding scheme, by the total number of bands. Dominated by sinks, which were recorded 3-5 strips. A significant correlation between all metric indicators of the shell in this species has been established.
Helix albescens mollusk shell polymorphism was assessed by the frequency of each morph in the sample, calculated the average number of morphs (μ), the frequency of rare morphs (h), and calculated the similarity of the samples by phenetic characteristics (r). In populations of H. albescens from urban habitats, 11 morphs were found. Three main morphs (12345, 1(23)45, 12045) were present in all studied samples. The color of H. albescens shells is very diverse in both natural and urban habitats.
According to the variability of the Chondrula tridens martynovi shell, the hypotheses that the change in the shape of the shell is influenced by the type of vegetation, or by the humidity regime of the botop, or the level of anthropogenic load were experimentally tested. The size of shells depends on the level of anthropogenic impact and increases under conditions of high anthropogenic load. The development of the oral apparatus of mollusks does not depend on the type of vegetation, but depends on the level of moisture of the habitat and the level of its anthropogenic transformation. The elongation of the shell of the mollusk describes the opposite dynamics of height in relation to the width and depends on the level of anthropogenic load. Restructuring in the organization of the oral apparatus depends on the humidification of the habitat and the level of anthropogenic load. This allows the use of this species of mollusk as a bioindicator of the state of the environment.
Keywords: terrestrial mollusks, malacofauna, morphometric variability.
